Chronic bacterial infections are serious medical problems in the United States. In chronic bacterial infections, biofilms protect bacteria from antibiotics and immune response mechanisms, thus increasing the rates of reoccurring symptoms and resistance to antibiotics. We discovered four novel compounds in Phase I under this STTR project that prevent the formation and disrupt biofilms, and we expect to identify additional novel compounds in Phase II. We propose to use the strategies developed in Phase I to prioritize the other active samples that have been identified. We will elucidate the structures of the active compounds and characterize their biological activity as biofilm inhibitors or antibacterials. We will also continue the discovery process for additional active samples. This work will enable us to commercialize these compounds that regulate biofilms and to further optimize or methods and strategies by which to discover more novel compounds that regulate formation of biofilms that are needed for a wide range of applications. In the United States, the market for microbial biofilm inhibitors is contained within the $8.5 billion market for antibiotics. Biofilms are involved in 65% of human bacterial infections; accordingly, biofilm inhibitors could capture a $4 to $6-billion segment of the antibiotic market. Biofilm inhibitors will have the greatest medical impact by treating many chronic infections, reducing catheter- and medical device-related infections, and in treating cystic fibrosis patients. Research has clearly established that biofilms play a significant role in these areas, representing a large market whose needs are unmet. The potential market penetration for potent biofilm inhibitors is exemplified by the sheer number of cases in which biofilms cause medical problems. [unreadable] [unreadable]